Electronic heat treating device



H. F. KlNCAiD ET AL 2,752,148

ELECTRONIC HEAT TREATING DEVICE June 26, 1956 Original Filed Sept. 8, 1948 Pre flea z United States Patent ELECTRONIC HEAT TREATING DEVICE Homer F. Kincaid, Carbon Clifi, 111., John 1). Graham, Louisville, Ky., Delos J. Reynolds, Chicago, 111., and Edward M. Wharti, Baltimore, Md, assignors to Westinghouse Electric Corporation, a corporation of Penn= sylvania, and International Harvester Company, a corporation of New Jersey, jointly Original application September 3, 1948, Serial No. 48,296, new Patent No. 2,657,301, dated October 27, 1953. Divided and this application June 22, 1953, Serial No. 363,143

9 Claims. (Cl. 266-) This invention relates to an apparatus for heat treating metal articles. More particularly, this invention relates to an apparatus that is automatically operable to subject a plurality of metal articles to a complete heat treating cycle for the purpose of producing a hardened surface on the article treated.

This is a division of parent application filed September 8, 1948, Serial No. 48,296, now Patent No. 2,657,301, granted October 27, 1953 and assigned to the assignees of this invention.

The speed with which metal articles are heat treated by induction is well known to those familiar with the art. In the treatment of articles having irregular contours such as gears, racks and sprockets, it is desirable to subject the articles to certain definite novel treating processes in order to secure an efiicient article having a surface zone hardened to a predetermined hardness. Such a process is clearly set forth in the H. F. Kincaid et a1. application Serial No. 759,888 entitled Heat Treatment of Irregular Objects, filed July 9, 1947, now Patent No. 2,564,906, granted August 21, 1951. In a process of the type disclosed in the aforementioned application a number of heating and quenching stations are provided and the article to be treated is subjected to a certain operation at each sttaion. It can readily be appreciated that in a process of this type the time factor is of great importance and it is therefore desirable to provide an apparatus that will deliver the articles to the station promptly and uniformly so that a uniform hardened article will result. It is applicants prime object, therefore, to provide a novel heat treating apparatus that is effective to heat treat an article in an etficient and uniform manner.

Another object is to provide an apparatus for heat treating metal articles, said apparatus including a plurality of inductor rings and means for providing an electromagnetic field within the rings.

These and other objects will become more apparent as the description proceeds and upon an examination of the accompanying drawings.

In the drawing:

The figure of the drawing is a schematic diagram for the heat treating apparatus.

The operation of the system is initiated by closing a manually actuable start switch 401. Actuation of this switch closes a circuit extending from a hot terminal 433 of a power supply (not shown) through the switch 451, the exciting coil 405 of a main control relay to ground. This relay is now actuated closing a circuit through a coil 4137 for actuating contaetors 409 and 411 which close the supply circuits through the preheat and postheat low frequency generators 413 and 415, respectively. The latter are preferably of the motor-generatorset type although they may be of the electronic type.

The closure of the start switch 401 also closes a circuit from the terminal 403 through the switch, the exciting coil 417 of an initiating relay to ground. This initiating "ice relay is now actuated initiating the operation of the various components of the system.

The actuation of a start switch also closes a circuit extending from the terminal 403 through an intermediate fixed contact 419 of the switch, the exciting coil 421 of a lock-in relay to ground. This lock-in relay picks up and closes a circuit from a hot terminal 423 of the supply through its contactor 425, the exciting coil 427 of a second lock-in relay to ground. Through a contactor 429 of the latter lock-in relay (427) and through one of its own contactors 431 the initiating relay (417) is locked in.

The switch 491 may now be released. With the switch released the first lock-in relay (421) remains energized in a circuit extending from a hot terminal 433 of the supply through a normally closed cam actuated switch 435, the exciting coil 421 of the relay to ground.

When the initiating relay (417) is actuated, a circuit is closed through the coil 437 for actuating the cammotor contactor 439 which extends from a hot terminal 441 through a STOP button 443, a now closed contactor 445 of the initiating relay, the exciting coil 437 to ground. The circuit through the cam motor 447 is now closed and locked in through a contactor 449 of the cam-motor relay (437). Another circuit is also closed through the coil 451 for actuating the contactor 453 for the spindle motor 455. This circuit extends from a hot terminal 457 of the supply through another STOP button 459, another now closed contactor 461 of the initiatingrelay (417 the exciting coil 451 of the spindle motor contactor to ground. The spindle motor 455 is now energized and the spindles are rotated. The spindle motor contactor is locked in through another contactor 463 of the relay (451).

The operation of the cam motor 447 causes the cam 238 to rotate and to actaute the bridge-lift valve 237. Fluid is injected into cylinder 115 and the spindle bridge 35 is lifted. The spindles 9t engage any gears that happen to be disposed on the trays 37 with which they are coaxial and raise the gears into the coils at stations 1, 2, 3 and 4, the quench rings at stations 5 and 6 and the coils at stations 8 to 11. The gears engage the casings 132 and raise the supports 137.

Each of these tubes of supports 137 carries a earn 471 for actuating the contact 473 of a switch which is open when the bridge is in the lowered position. When the tubes 137 are raised by the operation of the bridge, these switches (473) are closed. A switch (473) is thus closed at each position at which the spindle engages and raises a gear. These switches are connected in parallel with the cam operated switch 435 and maintain the circuit through the exciting coil of the lock-in relay (421) closed when the cam operated switch 435 is opened by the cam 475. lust after the bridge is raised, the cam 475 rotates to a position at which it opens the switch 435 for a short time interval. If there are no gears on any of the spindles 9t) raised by the bridge at this time, the circuit through the exciting coil 421 of the first lock-in relay is opened and this lock-in relay drops out. However, the second lock-in relay (427) which shunts out the start switch 491 at this time remains pulled up through a second cam actuated switch 477. The circuit through this latter cam actuated switch extends from a hot terminal 479 of the supply through the switch 477, the exciting coil 427 of the relay to ground. In the absence of gears on any of the spindles 90, the first lock-in relay (421) accordingly opens but does not at once cause the circuit through the start switch lock-in relay (427) to open. The cam motor 447 continues to operate and the valve 237 passes through a cycle during which it lowers the bridge 85 to its initial position. Shortly after the bridge is lowered to its initial position the second cam actuated switch 477 opens, opening the circuit through the exciting coil 427 of the start switch lock-in relay. Since the switch 491 is now open, the'initiating'relay (417) is de-energized and the operation of the system is stopped.

, If when the bridge 85 is raised, the spindles 9t) carry one or more gears, the corresponding spindle limit relays-99, a bridge limit switch 491, the solenoid 591 for valve 233 to ground. Valve 233 is now operated and a gear, if any is present on the spindle at station 5, is raised into the heating ring 23 at this station. A bridge limit switch 593 is closed when the spindle at station 5 rises to its uppermost position closing a circuit which extends from a.hot terminal 505 of the power supply through this limit switch, a now closed contactor 507 of the initiating relay (417), the exciting coil 509 of a relay which is slow to pick up to ground. The latter relay (509) remains in its initial position for a short. time interval and a circuit is closed through its contactor 511 and through the exciting coil 513 of a timer relayj The timer relay (513) now picks up, closing atone of its contactors 515 a circuit through the operating coil of a counter 517 which indicates that one treatment is in process. At its other contactor 519'the timer relay closes a circuit through the initiating mechanism (not shown) of'a timer'52l.

' This timer is preferably electronic and includes timing components (not shown) which may be of the usual capacity-resistor network type and a plurality of pairs of contacts 523, 525 and 527 respectively. Of these contacts, 523 and. 525 are closed immediately after the timer relay (513) is actuated; the other 527 is closed when the timing period for the timer 521 expires. V

Timers which would serve the purposes of our invention are available inlarge numbersin the art. A representative type is shown in a copending application, Serial No. 16,860, filed March 24, 1948, to Edward C. Hartwig and assigned to the Westinghouse Electric Corporation, which has now issued a as United States Patent No. 2,533,318. The Hartwig timer is designed to perform a larger number of functions than is involved here but can be modified to satisfy the present purposes.

At the now closed contact 525, the timer relay (513) is locked in. At the now closed contact 523, a circuit is closed through the exciting coil 529 of a contactor for the contour heater 531. This contactor (529) is now closed, energizing the high frequency contour heater, and any gear disposed'in the heater ring 23 is heated by induction.

While the timer 521 is passing through its timing operation, the sluggish relay (5439) operates. The timer relay (513 however, remains energized. The actuation of the sluggish relay (509) precludes a second actuation of the timer relay (513) once the timing operation is completed and the timer relay is de-energized.

When the timer 521 completes one'pha'se of its operation, the contact 523 is opened, opening the contour heater circuit. The contact 525 opens, resetting timer relay (513). The other contact 527 closes at the end of the first phase of the operation and remains closed.

When contact 527-cl0ses, it closes a circuit extending from a how/terminal 533 of the supply through the contacts, a normally closed contactor 535 of a terminating relay 537, the exciting coil of the auxiliary relay 499 to ground. The latter relay (499) is actuated, opening the circuit through the solenoid 501 of the valve 233. The gear at station Sis now dropped by the spindle to the quench ring 29 at the level of the other gears.

Through now closed contactor 527 the initiating circuit for the quench timer 541 is also closed. The quench terminal 545 through the exciting coil 547 of the quench relay to ground. The quench relay (547) drops out, closing a circuit through a normally closed contactor 549 of the terminating relay 537 and the solenoid 551 for valve 24%. Valve 248 operates, releasing quenching fluid and air for blowing oil any gear at station 7. v

While these events are taking place the cam motor 447 continues to rotate. Eventually cam 23% reaches a position at which the valve 237 operates. The fluid from cylinder 115 is now exhausted and bridge begins to drop, opening the limit switch 491.

Before the bridge has dropped substantially, 'a cam switch 561 is closed momentarily. A circuit is then closed which extends from a hot terminal 563 of the supply through the cam switch 561, a conductor, the exciting coil of the terminating relay 537 to ground. This relay is immediately actuated and is locked in through one of its closed contactors 565 and the now closed contactor 567 of the quench relay (547). At one of its now open .contactors 549, the termination relay 537 opens the circuit of the solenoid 551 for valve 248. This valve operates exhaustingthe cylinder 220 and stopping the flow of quench liquid and air. At another now open contactor 535, the circuit through the exciting coil of theauxiliary relay 499 is opened and the latter resets. for another operation. Since the bridge limit switch 491 is now open, the solenoid 501 remains currentless.

The bridge 85 now drops to its initial position. The earn 238 continues to rotate eventually closing valve 243. Rod 53 is now actuated, advancing the gears each to the succeeding station. The system is now in a condition for a repeat operation. 7

During the succeeding operation contact 527 opens.

when the timer 521 is initially actuated on actuation of the timer relay (513). When contact 527 opens quench timer 541 resets. The quench relay (547) is now actuated opening its contact 567 and resetting the terminating heating operation and the initiation of the quench operation, is of the order of .3 of a second. A gear deposited on a tray 37 passes through the machine' and is' discharged in a time interval of the orderof one minute after it is deposited.

it can now be seen that a novel heat treating apparatus 7 has been provided which will fully accomplish the desired objects of the inyention. It must be understood, of course, that changes and variations may be made which do not depart from the spirit of the invention as disclosed.

nor the scope thereof as defined in the appended claims.

We claim as our invention: 7 a 1. In heat treating apparatusincluding a conveyor of articles, the combination of first switch connections responsive to said articles; a motor for actuating said conveyor, second switch connections interposed between said first switch connections and said motor for periodically.

testing said firstswitch connections to determine if said first switch connections have responded to anarticle and if not to prepare said motor for stopping, and third switch connections responsive to said second switch connections for stopping saidmotor with said conveyor in 'a'predetermined position in the absence of articles on said conveyor.

2. in heat treating apparatus including a conveyor of articles, the combination of first switch connections responsive to said articles; a motor for actuating said conveyor, second switch connections interposed between said first switch connections and said motor for periodically testing said first switch connections to determine if the latter have responded to an article and if the latter have not so responded to prepare said motor for stopping, and third switch connections responsive to said second switch connections for stopping said motor with said conveyor in a predetermined position in the absence of articles on said conveyor, said second and third switch connections including switches actuable periodically by said motor.

3. In heat treating apparatus including an article conveyor having a receptacle for an article, the combination of a motor for raising said receptacle, first switch connections responsive to said article when said receptacle is raised, and second switch connections responsive to said first switch connections for actuating said motor to raise and drop said receptacle repeatedly if an article is present thereon and for stopping said motor in the lower position of said receptacle in the absence of an article thereon.

4. In heat treating apparatus including an article conveyor having a receptacle for each article, said receptacle having upper and lower positions, the combination of first switch connections responsive to said article on said receptacle in dependence upon the position of said receptacle, a motor for raising and lowering said receptacle, and second switch connections responsive to said first switch connections to actuate said motor to raise said receptacle and maintain it in the raised position for a predetermined time interval if an article is present in the receptacle and to stop said motor with said receptacle in the lower position in the absence of an article thereon.

5. In heat treating apparatus, the combination of an article conveyor having a first receptacle for an article, with said first receptacle having upper and lower positions, and a second receptacle for said article, with said second receptacle having a lower position in the upper position of said first receptacle and an upper position, a motor for raising and dropping said second receptacle, first switch connections responsive to said first receptacle when it is in the upper position for actuating said motor to raise said second receptacle to the upper position, second switch connections responsive to said second receptacle when it is in the upper position for controlling the heat treatment of said article in the raised position of said second receptacle, third switch connections responsive to said second switch connections for actuating said motor to drop said second receptacle to its lower position after said article has been heated a predetermined time interval, and fourth switch connections responsive to said second switch connections for controlling the quenching of said article after it has been dropped.

6. In heat treatment apparatus the combination of an article conveyor having a first receptacle for an article, and a second receptacle for said article, a first motor for moving said first receptacle between first and second positions, first switch connections responsive to said first receptacle when it is in said first position, a second motor 6 tor moving said second receptacle between first and second stations, second switch connections responsive to said second receptacle when it is in said first station, third switch connections responsive to said first switch connections when said first receptacle is in said first position for actuating said second motor to move said second receptacle to said first station fourth switch connections responsive to said second switch connections for applying a first treatment to said article in said first station for a predetermined time interval and thereafter moving said second receptacle to said second station, and fifth switch connections responsive to said fourth switch connections for applying a second treatment to said article in said other station.

7. In apparatus including a conveyor for the heat treatment of a metallic article, the combination of a bridge member adapted to lift said article from said conveyor, a motor member adapted for lifting said bridge member, a first switch member which is responsive to said article when so lifted, and a cam operated switch member connected to said motor member and adapted to cooperate with said first switch member to stop the operation of said bridge member after a predetermined period of time in the absence of said metallic article to be lifted from said conveyor.

8. In a conveyor apparatus for carrying an article to be treated, the combination of a motor apparatus for removing said article from said conveyor, a switch mechanism responsive to the position of said article, a first cam operated switch mechanism interposed between said switch mechanism and said motor apparatus for testing at a period determined by the cam contour to determine if said switch mechanism has responded to said article and it it has not so responded to prepare said motor for stopping, and a second cam operated switch mechanism connected to said motor apparatus for stopping said motor with said conveyor in a predetermined position in the absence of an article on said conveyor.

9. In heat treating apparatus operable from a suitable source of power and including a workpiece conveyor, the combination of a motor for actuating said conveyor, a first switch member connected between said source and said motor for actuating said conveyor, said first switch member being responsive to the presence of a workpiece on said conveyor, a second switch member connected between said source and said motor and being operable to periodically test said first switch member to determine if the latter member has responded to a workpiece and if said latter member has not so responded to prepare said motor for stopping the actuation of said conveyor, and a third switch member responsive to said second switch member for stopping said motor when the conveyor is in a predetermined position if the first switch member has not responded to a workpiece.

References Cited in the file of this patent UNITED STATES PATENTS 2,288,129 Feldhausen June 30, 1942 2,448,657 Bucknam Sept. 7, 1948 2,506,425 Journeaux May 2, 1950 

